A video-based observation method to assess musculoskeletal load in kitchen work.

This paper describes a new video-based observation method aimed to assess musculoskeletal load in kitchen work, aspects of its repeatability and validity, and problems confronted by the observers. Two pairs of researchers observed individually 117 video clips recorded in kitchens. Interobserver repeatability was assessed by computing the proportion of agreement and weighted kappa values (kappa(w)). Validity was analyzed by studying the distribution of the assessments over the rating scales and the ratings before and after the interventions, which were compared with expert assessments made from the same intervention targets. The proportion of agreement ranged from 57 to 88%. Interobserver repeatability based on weighted kappa values was mainly good to moderate. The method detected the changes in physical load due to the interventions. Direction of the changes corresponded with the expert assessments. Further development of the method is needed to assess the load on the hands and wrists.

Co-occurrence of musculoskeletal pain among female kitchen workers.

OBJECTIVES: The co-occurrence of musculoskeletal pain symptoms in seven body sites and their combinations among women in kitchen work were studied. METHODS: Data on musculoskeletal pain during the past 3 months in the neck, shoulders, forearms/hands, low back, hips, knees and ankles/feet were gathered by questionnaire from 495 female workers (mean age 45 years) in connection with an ergonomic intervention study in municipal kitchens of four cities in Finland. Altogether 122 kitchens (60% of those eligible) participated in the study. The response rate in the participating kitchens was 98%. RESULTS: The 3-month prevalence of any musculoskeletal pain was 87%, the most common sites being the neck (71%), low back (50%) and forearms/hands (49%). About 73% of the subjects had pain in at least two, 36% in four or more, and 10% in 6-7 sites. In pair wise comparisons, e.g. neck pain was associated with pain in other sites with prevalence ratios (PR) varying from 1.3 to 1.6, and ankle or foot pain with ratios between 1.9 and 2.4. The seven pain symptoms occurred in more than 80 different combinations. When the co-occurrence of pain was studied in three larger anatomical areas, i.e. any pain in the axial (neck and low back), upper limb and lower limb areas, subjects reporting concurrent pain in all three were the largest category (36% of the respondents). Altogether 53% of the workers reported pain in at least the axial and upper limb areas, and 48% in at least the axial and lower limb areas. CONCLUSIONS: Widespread co-occurrence of musculoskeletal pain symptoms was common among female kitchen workers with slight predominance in the upper body.

Sleepiness in various shift combinations of irregular shift systems.

The present study examined the occurrence of sleepiness in various shift combinations ending with a night or morning shift. Three weeks' sleep/work shift diary data, collected from 126 randomly selected train drivers and 104 traffic controllers, were used in statistical analyses. The occurrence of sleepiness at work (i.e., Karolinska Sleepiness Scale 7 or higher) was tested with a generalised linear model with repeated measurements including explanatory factors related to shifts, sleep, and individual characteristics. The prevalence of severe sleepiness varied between 25% and 62% in the combinations ending with a night shift and between 12% and 27% in the combinations ending with a morning shift. The occurrence of sleepiness did not, however, systematically vary between the shift combinations in either case. An increased risk for sleepiness was associated with high sleep need and long shift duration in the night shift and with high sleep need, short main sleep period, long shift duration and an early shift starting time in the morning shift. Also having a child was associated with an increased risk for sleepiness in the night shift. The results suggest that the shift history of 24-36 h prior to the night and the morning shift is not strongly associated with the occurrence of sleepiness at work, but there are other factors, such as shift length and starting time and sleep need, that affect a risk for sleepiness at work.

Sleep-wake rhythm in an irregular shift system.

Sleep in shift work has been studied extensively in regular shift systems but to a lesser degree in irregular shifts. Our main aim was to examine the sleep-wake rhythm in shift combinations ending with the night or the morning shift in two irregular shift systems. Three weeks' sleep/work shift diary data, collected from 126 randomly selected train drivers and 104 traffic controllers, were used in statistical analyses including a linear mixed model and a generalized linear model for repeated measurements. The results showed that the sleep-wake rhythm was significantly affected by the shift combinations. The main sleep period before the first night shift shortened by about 2 h when the morning shift immediately preceded the night shift as compared with the combination containing at least 36 h of free time before the night shift (reference combination). The main sleep period before the night shift was most curtailed between two night shifts, on average by 2.9 and 3.5 h among the drivers and the controllers, respectively, as compared with the reference combination. Afternoon napping increased when the morning or the day shift immediately preceded the night shift, the odds being 4.35-4.84 in comparison with the reference combination. The main sleep period before the morning shift became 0.5 h shorter when the evening shift preceded the morning shift in comparison with the sleep period after a free day. The risk for dozing off during the shift was associated only with the shift length, increasing by 17 and 35% for each working hour in the morning and the night shift, respectively. The results demonstrate advantageous and disadvantageous shift combinations in relation to sleep and make it possible to improve the ergonomy of irregular shift systems.

Nasal cell micronuclei, cytology and clinical symptoms in stainless steel production workers exposed to chromium.

The objective of the present study was to determine whether workers in stainless steel production with low exposure to various forms of chromium show an increase in micronucleated nasal cells or an excess of nasal symptoms or disease. Altogether, 48 workers employed in a stainless steel production chain were studied, 29 of them in the steel melting shop with exposure to hexavalent chromium (Cr(6+)), 14 in the sintering and crushing departments of the ferrochromium plant with exposure to trivalent chromium (Cr(3+)) and five in the mine with exposure to chromite ore (Cr(3+)). Thirty-nine workers from the cold rolling mill, with very low exposure to chromium, served as referents. All the subjects were never smokers with a minimum of 14 years employment in the same department. There were no significant differences between the exposure groups and the referents regarding the mean frequency of centromere-negative or centromere-positive micronuclei (studied by pancentromeric fluorescence in situ hybridization), nasal diseases and symptoms or mucociliary clearance of the nasal cavity. No statistically significant differences in the incidence of cell atypia or inflammatory cells were detected between the exposed workers and the reference group, except for an increase in lymphocytes among the chromite ore workers. Anterior rhinoscopy indicated slight inflammatory changes in nasal mucosa and secretion more often in the Cr(6+) and Cr(3+) groups than in the referents, the Cr(6+)-exposed workers showing more livid or oedemic epithelium. In conclusion, the stainless steel production workers, with low exposure to dusts or fumes containing hexavalent or trivalent chromium, did not show clinical changes in the nasal mucosa or an increase in nasal cell micronuclei or symptoms of nasal diseases, except for slight changes in the nasal epithelium and secretion.

Monoterpene and wood dust exposures: work-related symptoms among Finnish sawmill workers.

BACKGROUND: Monoterpenes and wood dust are released into the work environment during sawing of fresh wood. Symptoms related to exposure to monoterpenes and wood dust include irritation of the eyes, mucous membrane, and skin. METHODS: We studied 22 sawhouse workers who process pine and spruce in 1997-99. Exposure to monoterpenes was assessed by determining monoterpenes in air and verbenols in urine by gas chromatography using flame ionization detection. Wood dust was determined gravimetrically. A questionnaire was used to evaluate work-related subjective symptoms. RESULTS: Exposures to monoterpenes (geometric mean, GM) among sawhouse workers were 61-138 mg/m(3) and 2.0-13 mg/m(3) during processing of pine and spruce, respectively. Urinary verbenol correlated well with worker exposure to the alpha-pinene fraction of monoterpenes. The inhalable dust concentration in the breathing zone was 0.5- 2.2 mg/m(3) during pine processing and 0.4-1.9 mg/m(3) during spruce processing. The prevalence of symptoms, in the eyes or respiratory tract, was high during both seasons and in connection with either tree species. CONCLUSIONS: The highest monoterpene concentration (GM), in the breathing zone, measured during processing of pine, was less than one-fourth of the Finnish occupational exposure limit (OEL, 570 mg/m(3)). Verbenol concentrations in postshift urine samples reflected accurately the exposure to monoterpenes. The concentrations of inhalable dust (GM) were less than one-half the Finnish OEL (5 mg/m(3)). No significant differences in dust exposure were observed among tree species processed. Work-related symptoms appeared to correlate with monoterpene exposure during processing of pine and with wood dust exposure during processing of spruce.